I am 91 Widow in good health so far, still driving. I've taken a nap almost every day of my life, when home in the afternoon.
I can't say it's from fatigue just a habit, I nap about 20 min, get up and have coffee.
I get tired and have to set down a few minutes when I make my bed, especially when changing it, and jobs like that.
If I walk to far my legs get so tired, I have to set down. I agree with you "Fatigue seems to grow as age advances"
I started Tap dancing at age of 59 for17 yrs. every week, but now balance is effy, guess it didn't completely
help.